Question: What service with the largest port is a directory?
Paraphrase: What benefit with the biggest harbour may be a directory?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q756230 . ?ent wdt:P1641 ?obj . ?ent wdt:P31 wd:Q756230 } ORDER BY DESC(?obj)LIMIT 5 
Answer: Lightweight Directory Access Protocol